I haven't done anything with forced induction, but I've got a 434 (stroked 400) that Tim Meyer and I put together, and it dyno'ed at 504hp/544tq. Granted, it cost a small fortune, and I wouldn't recommend going the 400 route for anything over around 425-450hp as the 460 would then begin to be the better bang for the buck. I did have to have my block machined for 4-bolt, and there were a number of other issues that had to be addressed, but I was bound and determined to get the best power I could with good idle characteristics and good vacuum, all while running on pump gas.

As Tim would attest, we could have gotten more power out of it still, but then I'd start losing streetability (lopey idle, bad vacuum, etc). The reason I went this more expensive route was that in 1979, you couldn't get a Ford truck 4x4 with anything bigger than a 400 (a two wheel drive you could get the 460, but not in a 4x4 from the factory unless it was special order)....so I figured I'd stick to the original theme. That, and not many people do what I've done, and I like taking the road less traveled.

So, it will depend seriously on what kind of power you're going to end up wanting....you can get to high numbers with the 400, but after 425-450hp it's going to start costing a LOT more. The 460 would be the better choice for bang for the buck in that regard. If, however, you want to stay under that limit, then the 400 is every bit as easy to get those numbers from (cheaper if you already have the block). That's why I warn people not to take the numbers from my plant as a typical sort of thing....it was not what one might call a "budget build". I knew anything over a certain hp rating would begin to cost more, and I do think that line is right at 425-450 like Sleepy said.

As for forced induction? That could change the number slightly....if you built the block well: 4-bolt mains, kept to a 400 stroke (as 4.25" of stroke might not hang in there as long under forced induction conditions...not sure), and had intake and heads that could breathe in accordance with the amount of boost you'd run, then maybe the numbers could be higher without breaking the bank. My gut tells me that's not actually the case, but I could be wrong. It always takes somebody with the time, money, and weirdness to try....anything is possible. Personally, I think it'd break the bank with regard to a "budget", as I said, you'd be into the plant for heads, intake, good block build, all the internals, not to mention the power adder. So, as much as I'm fond of the 400, I'd still say that the 460 is the way to go for anything over that 425-450 limit.

 

This is all very helpful information. If I was to go for any kind of hp significantly over the 400hp range it wouldn't be for a few years yet. Would there be a significant price difference for now between getting/building a 460 up to say 450hp and then doing the swap, compared to just building the 351 up to 400+ hp. It sounds like a 460 would be my best bet for the long run, but a 351 would be cheaper for now??

 

throw $100 at that 351 and turn it into a 400. the 400's 4" stroke is the BEST thing you can do to that 351. the most you can get outta that 351 and keep it running decently is to throw a cam, intake, and headers on it. with a big enough cam, you could maybe get 250-300hp with the stock pistons and heads, which isn't so bad but it'll kill your low end torque. the problem with the 351m is the pistons. both me AND my dad have had nothing but piston problems with our 351m's. they're too tall and the wristpins are too low, so once they start to wear out, they wear QUICK. spend the $100 for the 400 crank and pistons, and throw another $150-$300 into the cam and valve train. it'll be pretty peppy then without killing your bottom end.

 

The one item that Justforkicks left out there, is probably about second most important. I agree that the crank and pistons is a first priority, but the second step is a straight up timing kit. These engines came with the factory timing retarded a number of degrees (can't remember how many...it's like 6 or more). That, paired with the low compression from the factory made for fairly gutless engines when there was no reason for them to be that way other than ever tightening emissions laws at the time.

I think if you give Tim a call he'd be able to help you with a shopping list that will get you the power you need for as little expenditure as possible. I think the short list would be: crank, pistons, timing kit, good cam, headers, carb, and intake. That should wake your 351m to the point that you'd not even recognize it (well, it'd look nearly identical, but it'd be a 400 and not a 351m anymore). Like you said, if it's going to be some time before you're looking to make big power, you can do all the research you want until then, and make an informed decision. Once you decide you want a lot of power, then you should seriously consider the 460 as the 400 will not be the cheaper way to go (trust me on that). I'm not saying the 400 can't make big power, as it can, but like the aforementioned example of John Kaase making over 600hp from a 400 is true, it should be mentioned that just the cylinder heads on that plant were from Cylinder Head Innovations (CHI), and that set cost over $5000.00 (it's on their website). My heads were nowhere near that, but they were still over $2k for the pair. So, again....I think for big numbers it'd be cheaper to start with a bigger engine.

Big power can be made from almost any engine.....but the amount of power obtained is directly proportionate to the depth of your wallet. If you want 500hp out of a 2.3L four cylinder, you can do it.....but it is going to cost you a mint (and salaries for engineers from NASA probably) to achieve it.

 

haha yeah, i forgot about that... i got a 400 out of a 71 merc so i think nothing of it anymore because i already have striaght up timing and flat topped pistons.

 

Ok, I'm definitely going to keep looking into this. I appreciate all of the information though, now I know exactly what i'm getting myself into! pics will be up when I start doing the mods.

 

in the lincoln mark 4 the stock 460 from what i have read is rated at 345 hp and 500 ft pounds of torque... hehe thats what i have in my truck i upgraded from a 360